Trojita is a light mail client for IMAP servers developed for the qt platform. It is fast and cross-platform and uses the available resources very efficiently. Download it from here.
This version is Qt-5 dependent and I have tested it on Porteus KDE5 successfully.

WARNING: Trojita won't work on POP3 servers

Enjoy!

Porteus is proud of the FASTEST KDE ever made.....(take akonadi, nepomuk and soprano out and you will have a decent OS).
The Porteus Community never sleeps!